Composite metal body.



W. D. COOLIDGE.

COMPOSITE METAL BODY.

APPLICATION FlLEl) MAR. 19. 1915.

1 ,162,342. Patented Nov. 30, 1915.

tungsten Qo1d-p1atin um 61 1 0H Inventor:

William D. Coolidge His Attorneg.

ran STATES PATENT curios.

WILLIAM COOLIDG-E, SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

COMPOSITE METAL BODY.

Specification of Letters Patent.

Patented Nov. 30, 1915.

Application filed March 19, 1915 Serial No. 15,464.

To all whom it may concern:

Be it known that I, WILLIAM D. Coomoon, I

a citizen of the United States, residing at Schenectady, in the. county of Schenectady, State of New York, have invented certain new and useful Improvements in Composite Metal Bodies, of which the following isa specification.

The present invention comprises a metal body consisting of tungsten or molybdenum and a layer of precious metal intimately united therewith which is useful for various purposes in the arts, as, for example, in

dentistry, as dental pins or the like.

Tungsten and molybdenumalthough substantially incorrodible are not wet by gold even when care is exercised to prevent oxidation.

I have discovered that when a small amount of platinum is alloyed with the gold, the tungsten 'or molybdenum is wet by the molten alloy' in an-atmosphere of hydrogen and a firm union is produced.

My inventioncomprises a composite body of tungsten or molybdenum joined to a laver of a gold-platinum alloy, as, for example, a rod or wire coated with gold-platinum alloy.

The accompanymg drawing shows partly in section'a metal article made inaccordance with my invention.

This new article of metal may be produced by melting gold containing about 1.5% of platinum in an alumina crucible in a hydrogen atmosphere and dipping-the tungsten or molybdenum, for example, as a rod or wire 1 of ductile. metal, into the molten alloy. A thin layer 2 of the gold-platinum alloy will unite firmly with the tungsten or.

molybdenum. The hydrogen not only prevents surface oxidation of the tungsten or molybdenum but also.enables the gold alloy to wet or adhere to the surface of the refractory metal. Other alloying metals, such,

for example, as palladium may also be added to the gold alloy to modify its melting point or its hardness.

The gold coated metal article. has the mechanical strength of tungsten or molybde-.

num, and the gold-coated surface is not only incorrodible but may readily be soldered or otherwise joined to other metals. The good mechanical properties of tungsten or molybdenum, particularly toughness and springiness are not lost at the high temperatures necessary for casting or soldering operations, say about 1000 to 1100 C.

While especially useful in dentistry this new metal article is not limited to this particular field. It may be used in the chemical industry or wherever a" substantially incorrodible, strong, resilient metal article is desired.

As above indicated, molybdenum is to be considered the equivalent of tungsten for the purposes of the present invention.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. A composite metal article comprising tungsten and a coating comprising an alloy of gold and platinum metallically united to or wetting said tungsten.

2. A metal article consisting of ductile Cerrection in Letters Patent Not 1,162,342.

' 1 Signed and sealed this' ll th day ef Jniiary, A. D., 1916 It is hereby certified that in'Letteie P a'tent No. 1,162,342, granted j-Ne v eihber 30, 1915, upen the application of Wiliiam D. Coolidge, of Sehenect edy, Nevi York,

for an improvement i1 1 C0mposite Metal Bodies,.--an errer appeers in the printed A specification reqhiring eorreetio as folipws: Page-'1, 1ine'25, for the Word "lever read lag eh," and that the said Letters latent sholild he read withrthis (:orreetion therein that the same may co forni to the recoi'd of the eeee in the Patent Oflice.

J. TLNEWTQNQ i i-Abting Uohtm'issiener;of 1 dtents., 01.29-1s2 V 

